Electronics Forum | Mon Mar 27 21:09:29 EST 2006 | ms
Thanks Dave I'm not convinced the air is necessarily in the paste from manufacture - suspicious that it may be folding in during the change in direction of the print cycle - or as the paste travels across apertures. It is not necessarily in the fir
Electronics Forum | Sun Mar 26 19:02:05 EST 2006 | ms
Hi We are running automatic stencil printers, open squeegees, stainless stencil, stainless blades, print speed 25-30mm/sec. We have a frustrating consistency issue printing .37x.3mm apertures on a 45pin LGA (11 pads each side, 1 large ground in mid
Electronics Forum | Wed May 08 11:07:54 EDT 2002 | Carol Stirling
We have a concern with moisture absorbtion/humidity effects on PWBs specifically used for automated SMT (including BGA). I'm sure there is a IPC spec on this and would appreciate the number - I've searched the IPC web-site -no results. Could you t
Electronics Forum | Thu May 09 17:28:33 EDT 2002 | davef
There is no IPC specification, nor should there be. * There are just too many peculiarities in the design and fabrication of PWB. * The issue is not defining how to store boards. The issue setting expectation for reliable products and allowing you th
Electronics Forum | Sat Jun 28 22:52:34 EDT 2003 | ramanandkini
We have an Electromechanical assembly (clock) that has a step motor on the board. This electromechanical assembly is assembled in a screw less plastic moulded casing. The plastic casing is neither air tight nor water proof. The board is with SMOBC+ H
Electronics Forum | Mon Mar 30 16:02:44 EST 1998 | Michael Allen
| We have successfully put .016" vias in .030" pads. | There is no issue with .030" solder balls, since | the actual volume of the .002" via in pad is small | compared to the ball+solder paste volume. | We did notice random bubbles where, apparentl
Electronics Forum | Mon Mar 27 15:10:48 EST 2006 | ms
Hi Steve Thanks for your reply. Your comments make it sound like it may be the nature of this paste. Any one else agree? Paste control is fairly good. Paste is put in fridge straight after it arrives at inwards goods, (4deg). Removed from fridge
Electronics Forum | Wed Mar 25 16:38:21 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no issue with .030" solder balls, since the actual volume of the .002" via in pad is small compared to the ball+solder paste volume. We did notice random bubbles where, apparently, the sol
Electronics Forum | Wed Mar 25 16:36:10 EST 1998 | Steve Joy
We have successfully put .016" vias in .030" pads. There is no drain off with .030" solder balls, since the actual volume in the .002" depression is low. We did notice random bubbles where, apparently, the solder reflowed and trapped the air in the
